The present invention relates to a device for connecting a beam to pillars or similar supporting structural elements for erecting buildings, particularly multistory buildings, by means of prefabricated concrete components.
As is known, the building method that uses prefabricated concrete components has, in recent years, become increasingly widespread mainly thanks to its reduced execution times compared to the traditional method of on-site building.
However, in some particular sectors, the prefabrication technique has not yet been able to expand fully.
One of these sectors is constituted by the erection of buildings used for office or residential purposes, particularly if they are of the multistory type.
Prefabricated concrete components are in fact currently scarcely applied in this field, because prefabricated beams, in order to withstand the loads to which they are subjected by using a coupling to the pillar that consists of simple resting thereon at their ends, have an excessive vertical space occupation.
On-site building operations are able to minimize the height of the beams thanks to the fact that with this construction method there is an uninterrupted continuity between the pillar and the beam.
Prefabrication instead entails, for the various parts that compose the building, a momentary discontinuity, which is eliminated only with final assembly. However, this fact entails that prefabricated beams, as mentioned, must be inevitably higher than beams built on-site.
The prefabrication method has tried to obviate these drawbacks by resorting to pre-stressing, which consists in loading the beam by compressing it beforehand so as to bend it upward. However, this solution is advantageous with considerable spans, i.e., distances between the pillars, otherwise the resulting saving in beam height and therefore the financial saving are insignificant.
However, it should be noted that the prefabrication method allows an unequalled erection speed as well as industrial-type production and quality control; moreover, the prefabrication method allows to build regardless of weather conditions, which instead can have a severe effect on on-site building, and makes the progress of work independent of the waiting time for the concrete to cure, which greatly slows down the erection of multistory buildings with the traditional method of on-site building.
In view of the undeniable advantages offered by the prefabrication method, the need is felt to be able to extend its application also to those fields which, for the reasons described above, have not yet been able to adopt this method.
U.S. Ser. No. 09/669,970 by the same Applicants discloses a device for connecting a beam to pillars or similar supporting structural elements for erecting buildings, particularly multistory buildings, by means of prefabricated concrete components that allows to reduce the height of the beam, despite the beam being prefabricated, without necessarily having to resort to prestressing of the beam.
Such device substantially comprises first means for connecting the two end regions of the beam to the pillars and second means for connecting two intermediate regions of the longitudinal extension of the beam to the pillars. The first connection means are constituted by connection means of the interlocking type, while the second connection means comprise at least two inclined rigid tension elements, each element connecting an intermediate region of the longitudinal extension of the beam and a region of the respective pillar that is located at a higher vertical level than the region where the tension element is coupled to the beam.
During its testing and use, the device has proved to be susceptible of improvements aimed mainly at achieving a more uniform distribution of the stresses within the beam and at introducing a new static layout.